Automatic crossing gate



Sept. 28, 1937. n. G. CLARK x-:T--AL 2,094,094 i y AUTOMATIC CROSSING GATE Filed May 2o, 1935 ,z'sneets-sheef 1 Sept. 28, 1937. R. G. CLARK ET' AL AUTOMATIC CROSSING GATE Filed May 20, 1935 2 Sheets-Sheet 2 fnvefzfors .Xgayffzond Clar/E lfon Sml'zhJzf fornqy I Patented Sept. 28, 1937 UNITED STATES AUTOMATIC CROSSING GATE Raymond G. Clark, Milton Smith, Jr., and Morris McD. Dilley, Louisville, Ky.

Application May 20, 1935, Serial No. 22,344

5 Claims.

The present invention relates. to automatic crossing gates which are employed at opposite sides of a railway crossing, for example, to stop highway traffic during the approach of a train. More particularly, the invention relates to structures of the character having a hollow standard, a hollow head mounted on the upper end of the standard and a gate which both pivotally supported by the head for vertical movement into and out of operative position and rotationally carried by the head for horizontal movement to and from such position.

An important object of the invention is to pro-V vide a simple, inexpensive, flexible gate operating mechanism of novel form.

Another object is to provide a simple arrangement for eiecting the gate raising and lowering movements at different speeds.

A further object is to provide a mechanism which, upon a power failure such as might render the gate operating means inoperative, will enable the gate to move by gravity to some desired position, say the lowered position, should it happen at the time to be out of such position.

A further object is to provide in connection with a liquid operated gate raising and lowering means, a novel and readily accessible liquid reservoir.

The invention is illustrated in the accompanying drawings, wherein:

Figure l is a vertical sectional view of a structure embodying the invention in which the head is in its normal position;

Figure 2 is a section taken along line 2-2 of Figure 1;

Figure 3 is a top plan View with the cap removed;

Figures 4 and 5 are fragmentary views of the means by which the head is rotatably mounted on the standard, these views being taken respectively with the headl in and slightly out of normal position; o

Figure 6 is a perspective view of the bracket which supports the Worm gear in meshing relation with the ring gear;

Figure 7 is a section taken along line 'I-l of Figure 3;

Figure 8 is a section taken along line 8-8 of Figure 2; and

Figure 9 represents schematically, the relative arrangement of the motor reversing switch with respect to the track circuit and motor.

In the embodiment illustrated, a hollow standard I having suitable doors I-a, a hollow head 2 mounted on theupper end of the standard! and provided with a removable cap 3, a horizontal gate shaft 4 extending transversely through the head, and a gate 5are all shown in conventional relationship. The gate 5 is, of course, carried on the outer ends of the shaft i and ar- 5 ranged for movement vertically into and out of its` operative horizontal or lowered postion. It is also arranged for horizontal rotational movement about the standard l away from the crossing. This is to permit a vehicle, which may be 10 trapped on the crossing between lowered gates, to strike and horizontally move a gate and thus escape from the crossing ,without necessarily injuring either the gate or vehicle. It is accomplished by mounting the head 2 rotationally upon 35 the standard l through theagency of a series of irregularly spaced rollersv 6 which are secured to the upper end of the standard in position to engage the overlying head surface which is ysubstantially planar. In the normal position of the 20 head, irregularly spaced rollers B' extend into similarly spaced recesses 's formed in the roverlying surface of the head. These recesses should be made of a depth sufficient. merely to prevent the Wind from turning the gate. A greater depth 25 serves only to increase the initial turning forcek required and thus correspondingly increase the possibility of a gate being broken when struck by a trapped vehicle. The irregular spacing of the rollers 6 and recesses each other only in the normal position of the head. As a result, when the head is rotated out of its normal position, it will be elevated to an extent determined by the depth of the recesses and will remain elevated as long as it remains 35 out of normal position.

Now, in order to return the head to its normal position after horizontal movement therefrom, a

spring 8 is suitably connected between the standard I and the head. This spring may be of vany 40 suitable form and arrangement, but, as shown, is

inthe formof a cylindrical helix which is vertically arranged in the lower part of the standard I with its lower and upper ends respectively secured iixedly to a stationary cross member the standard I, and adjustably, to the base' IQ of a rotatable U-shaped bracket, the adjustment being efrected by placing the upper end or" the spring B into any one of a circular series of openings (not shown) in the base l. 50

The U-shaped bracket is rotatably carried by the head 2 through the securement of its upwardly extending arms I I to a pair of flanges I2` which depend downwardly from the lower end of head 2 at opposite sides of a rectangular opening vthere- 55 'lis such that they match 30 in. As a result, when the head 2 is horizontally turned from its normal position, the spring 8 is wound, thereby storing up the energy necessary to return the head. The rotation of the head 2 is centered by means of a core I3 depending from the base I downwardly through the spring 8 and cross-member 9. The lower end of core I3, which projects below the cross member, is enlarged to prevent the lifting of the head from the standard, the enlarged portion being spaced from the cross member sufficiently to provide the vertical clearance required for the rotational movement of the head 2 out of its normal position. While the gate may thus swing horizontally away from the crossing out of and back to its normal position, it is prevented from horizontally passing its normal position and swinging toward the crossing by the engagement, at that position, of a depending head lug I4 with a lateral standard lug I5, the latter being secured to the standard I between a pair of rollers 6.

The gate 5 is vertically operated by means of a reversible operating mechanism connected to the gate shaft 4, this mechanism being mounted to rotate with the head 2. The operating mechanism includes a turbine T driven by electric motor M through pump P and connected to drive the gate shaft 4 through worm gear I6 and ring gear I'I, the latter being mounted on the shaft. The motor M and pump P are directly coupled together and mounted on the base I0 of the U- shaped bracket. The pump P and turbine T are connected to each other through pipes I8 and I9, the turbine being mounted on an arm II of the U-shaped bracket with its impeller shaft aligned with and operatively connected to the worm gear I6, which meshes with ring gear I'I. The pump and turbine structures may be of any suitable reversible types and operated with any suitable fluid such as oil. Preferably, however, the turbine T is in the form of a helical gear pump which can be operatively driven in either direction by passing oil under pressure through it. The worm gear I6 is rotatably held in mesh with the ring gear I'I by means of bracket 2| and bracket plate 22. The plate 22 is bolted or otherwise secured to the top of the bracket, while the latter is rigidly mounted on an inner side wall of the head.

It is thus apparent that, when the motor M is rotated in one direction, the pump P will operate to circulate oil under pressure through one of the pipes, say I 8, into the turbine T and from the turbine through the other pipe I9 back to the pump. In this manner, the turbine is rotated and caused to drive the gate shaft 4, through shaft 20, gears I6 and II, thereby moving the gate 5, say, to its lower or operative position.

Should the gate, during its lowering movement, strike an obstacle, such as a vehicle, oil pressure will be built up in pipe I8 until the gate 5 or some other part breaks or otherwise yields to the driving force. To avoid this undesirable result, the pipe I8 is connected directly to pipe I9 by a normally closed adjustable relief valve 23 which opens, upon an undue rise in oil pressure, to permit the ow of oil directly from pipe I8 to pipe I9 thus by-passing it around the turbine. The same result is produced, during the gate raising movement, by an adjustable relief valve 24 which similarly permits a reverse ow of oil from pipe I 9 to pipe I8. It will, of course, be understood that the gate raising movement is eifected simply by reversing the rotation of the motor M.

In structures of this general Class, the motor M is usually of the type having three power terminals, namely, common, up and down (see Fig. 9). A motor of such character is herein contemplated and its reversal eiected by any suitable form of reversing switch as are now in such common use that illustration is not deemed necessary. These switches are normally controlled through a motor relay and function, when operated in one direction or the other, to change the power connections from up and common to down and common, or vice-versa.

In order to deenergize the motor M when the gate reaches its limit of movement in either direction, the limit switches of any suitable form and arrangement may be provided. In the present embodiment, these switches 25 and 26 are of the mercury type. They are located within the head 2 and their operation controlled, by the gate raising and lowering movement of the gate shaft 4, through a pair of arms 2'I and 28 which are secured to and extended radially from the shaft. The arms are angularly spaced about the shaft a distance corresponding to the full vertical movement of the gate from one position to the other. The limit switches 25 and 26, which are respectively connected in the up and down power lines of the motor, are respectively mounted on supports 25-a and 26--a, these supports being pivotally secured to the head. The support 25-a, for the up limit switch 25, is counter-balanced so that it normally tends to assume an inclined position in which its lower end extends into the line of movement of the switch operating arm 2'I at a point such that it will be engaged and moved upwardly by the arm 2T at the end of the upward movement of the gate. The support 26-a. for the down limit switch 26 is likewise arranged relatively to the switch operating arm 28 but reversely counter-weighted so as to tend normally to assume a reversely inclined position. Both of these switches operate to open their respective power lines only when moved from their inclined positions.

It will be apparent that with the gate arm in the up position, the switch arm 21 will be in contact with one end of the "up switch supporting member 25% holding that switch in its open circuit position. As the gate moves downwardly, the arm 2'I will likewise move downwardly and thus move away from the up switch, permitting it to return to the inclined position in which it closes the up circuit. The downward movement of the gate causes the arm 28 to approach and ultimately engage the raised end of the down switch supporting member 26-a, thereby moving it downwardly to open the down power line of the motor when the gate reaches the limit of its lowering movement. Naturally, upon raising the gate, the arm 28 will move upwardly away from the supporting member 26 permitting the down switch 26 to return, by gravity, to its closed circuit position.

The rate of speed at which the gates are lowered is, of course, limited. This speed should be slow enough to enable vehicle operators to avoid the gate space. Ordinarily, a lowering time of approximately fteen seconds is ample. On the other hand, it is desirable to raise the gates as quickly as possible in order to reduce the highway blocking time to a minimum. To this end, therefore, the operating mechanism is driven, in raising the gates, at the highest allowable speed. This enables the gates to be raised within a substantially shorter period than is necessary in lowering them. It also requires the provision Cil of means for reducing the speed of the operating mechanism in lowering the gates. For this purpose, an impedance or resistance R. suiicient to eiect the necessary speed reduction, is connected in the down power line of the motor M. Obviously, this resistance may be located at any suitable place in the line. For example, it may be connected directly in series between the down terminals of both the motor M and the reversing switch, as shown, or at any other suitable intermediate point.

With the arrangement thus far described, should a power failure render the motor inoperative, the gate will remain in such position as it may happen to be in at the time of such failure. Since a power failure might occur with the gate in any of its positions, it may be desirable, in some installations, to raise the gate upon a power failure occurring when the gate is not in such position and, in other installations, likewise to lower it. Accordingly, means, operative upon a power or circuit failure, are provided for disconnecting the gate from the operating mechanism, the gate being counter-weighted either to rise by gravity or to fall, as desired. While any suitable means for this purpose may be provided, the means illustrated consist of suitable mechanism for disconnecting the ring gear I1 from the gate shaft 4.

To this end, the ring gear I1 is loosely mounted on the shaft and positioned between a fixed collar 29 and a slidable collar 3U, which is secured to the shaft but slidably mounted to permit lateral movement along it. The slidable collar 30 is laterally movable from one position, in which it extends out of contact with the ring gear I'I, to another position, in which it contacts the ring gear IT. In this latter position, the contacting faces of the ring gear I1 and slidable collar 30 cooperate to provide a tongue and groove connection by which the ring gear is secured to the gate shaft 4, the tongue 3|, as shown, being on the collar. The slidable collar 30 is also provided with an endless peripheral groove 32 and its lateral movement eiected by the yoke 33, which surrounds the collar and which is slidably but not rotatably connected to it by a pair of diametrically opposed yoke pins 34 extending into opposed sections of the groove 32. The upper end of yoke 33 is pivotally connected to one end of a xed arm 35, the opposite end of which is suitably secured to the head. The slidable collar 30 is urged away from ring gear I1 by means of a spring 36 connected between the head 2 and the lower end of the yoke 33. This end of the yoke, however, is also connected to the plunger 31 of a solenoid 38. The solenoid is electrically connected so as to be energized during all periods when power is on, When energized, the solenoid plunger moves the lower end of the yoke toward the ring gear against the ac'- tion of spring 36, thereby moving the collar 30 into driving relation with the ring gear. Naturally, upon a power failure, the spring 36 becomes effective to make the disconnection permitting the gate to rise, for example, by gravity. When it reaches the raised position, the limit switch 25 will be operated to open the motor up circuit and thus condition the apparatus for normal operation when power is restored. The solenoid circuit is not illustrated since it may be readily connected into any of the various circuit systems used in controlling the operation .of apparatus of this general character.

Returning to the oil circulating system, it may be pointed out that either or both of the pipes i8 and I9 may be provided with extensions land IS-a extending upwardly into the head 2 and terminating near the removable cap 3. The ends of these extensions are preferably closed by suitable removable plugs or screw caps. These extensions function as oil reservoirs and their capped ends, being adjacent the cap 3, ailord an easy and convenient means of access to the oil system whereby the oil level can be readily inspected and additional oil added as required.

Having described our invention, we claim:-

1. A crossing gate including a standard, a gate supported by said standard and adapted for movement between operative and inoperative positions, a fluid turbine having a reversible impeller connected to said gate, and means for rotating said impeller at one speed in a direction such as to move said gate towards its operative position and at a substantially higher speed in the reverse direction.

2. A crossing gate including a standard, a gate supported by said standard and adapted for movement between operative and inoperative positions, a fluid turbine having an impeller connected to said gate, and means for furnishing fluid under pressure to said turbine to rotate said impeller and move the gate, a pressure relief means for icy-passing fluid around the turbine upon an undue rise in pressure in the fluid furnished to the turbine.

3. A crossing gate including a standard, a gate carrying shaft supported by said standard and operable between gate raised and lowered positions, a fluid turbine having an impeller connected to said gate, a motor driven pump for furnishing fluid under pressure to said turbine to rotate said impeller and move the gate, relief means for by-passing fluid around said turbine upon an undue rise in pressure in the fluid furnished the turbine, a motor limit switch for opening the motor circuit when the gate carrying shaft reaches the limit of its movement in either direction, and means carried by the shaft for operating said limit switch.

4. A crossing gate including a standard part, a head part, and means rotatably supporting said head on said stand-ard for horizontal rotational movement out of the normal position of said head relatively to said standard, said means including spaced rollers on one part and a substantially planar track on the other, the track having spaced roller receiving recesses which match with the rollers and into which the rollers extend in the normal position of the head.

5. A crossing gate including a standard part, a head part, and means rotatably supporting said head on the standard for horizontal rotational movement of the head out of its normal position on the standard, said means including irregularly spaced rollers on one part and a substantially planar track on the other, the track having similarly spaced roller receiving recesses which match with the rollers and into which the rollers extend only in the normal position of the head.

RAYMOND G. CLARK. MILTON SMITH, JR. MORRIS MCD. DILLEY. 

